Repeater fuse switch



Oct. 8, 1940. c. A. Fox

REPEATER FUSE SWITCH 2 Sheets-Sheet 1 Filed July 2, 1957 Oct. 8, 1940. c. A. Fox

REPEATER FUSE SWITCH Filed Julyy 2. 1957 2 Sheets-Sheet 2 7 una?.

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/ TTOENEV Patented oct. s, 1940y UNITED STATES PATENT OFFICE REPEATER FUSE SWITCH Application July 2, 1937, Serial No.7151,587

6 Claims.

This invention relates generally to electrical fuse switches and more specifically to a switch of the general type disclosed in United States Letters Patent No. 2,086,028, dated July 6, 1937,

the predominant object of the present invention being to provide an improved switch of the general type disclosed in the Letters Patent identifiedv above which instead of being a single operating switch, as is the structure of said patent, is provided with a plurality of units adapted for sequential operation to provide a repeater type switch.

Fig. 1 is a plan view of the improved switch.

Fig. 2 is a side elevation of the switch illustrated in Fig. l.

Fig. 3 is a front elevation of the switch illustrated in Figs. 1 and 2.

Fig. 4 is a horizontal section taken on line 4--4 of Fig. 3.

Fig. 5 is a horizontal section on line 5-5 of Fig. 2.

Fig. 6 illustrates a modified form of the invention adapted for use in direct mechanical association with a transformer.

In the drawings, wherein are shown for the purpose of illustration, merely, two embodiments of the invention A designates in Figs. 1 to 4 inclusive the improved switch generally. The switch A includes a suitable insulator B to which is attached a bracket C that serves as means for securing the switch A to a cross arm or other support.

Secured to the insulator B adjacent to the up'- per end thereof is the upper terminal I of the improved switch, said upper terminal including a block la which is provided with an arcuate face which contacts with the curved surface of the insulator, and a rigid arm Ib that extends upwardly from said block. The arm Ib of the up- 40 per terminal has associated therewith a suitable connector 2 for electrically connecting an electrical conductor (not shown) to the upper terminal.

Associated with the upper terminal I is an upper contact 3 which preferably, though not necessarily, is formed of rather heavywire possessing resiliency. The upper contact 3 includes a portion 3a which embraces the insulator, this embracing portion being disposed in an annular groove formed in the insulator. Also the upper contact includes a pair of slightly convergent portions which extend forwardly from the insulator embracing portion, and at points adjacent to the opposite sides of the block of the upper terminal, eyes 4 are formed in the forwardly ex- (Cl. 20o-126) tended portions of the upper contact. Extended through the eyes 4 and through opposed washer elements 5 is a bolt 6 which serves to draw the forwardly extended portions of the upper contact toward each other whereby the insulator 5 embracing portion is caused to grip the insulator tightly and the upper terminal is securely attached to the insulator B.

Adjacent to the forward end of the upper contact 3 a sleeve I is provided which embraces the forwardly extended portions of said upper contact so as to prevent undue spreading of said forwardly extended portions. Also at the extreme outer end of the upper contact the forwardly extended portions thereof are bent rearwardly upon themselves as indicated at 8 and the rear end portions of said rearwardly bent portions are flared outwardly and bent downwardly slightly as indicated at 9. As will be presently made plain herein the rearwardly bent forward portions 8 of the upper'contact provide gripping portions which receive portions of fuse links associated with the switch, and the ared and downwardly bent portions serve to guide the portions of the fuse links into said gripping portions. In order to prevent the rearwardly bent portions 8 from moving outwardly to an unnecessary degree and thereby destroying the gripping action of the gripping portions of the upper contact a cap Ill is frictionally applied to the outer end of the upper contact, in embracing relation with respect thereto, as shown in Figs. 1, 2, and 3.

As shown clearly in Figs. l, 2, and 3 of the drawings, the improved switch A includes a pair of lower contacts, one thereof, which is designated by the reference' character II, being attached to the insulator B at a point adjacent to the lower end thereof, and the other lower contact, which is designated by the reference character I2, being attached to the insulator at a point a slight distance above the point of attachment of said lower contact II.` The means for attaching the lower contact I2 to the insulator B includes an arcuate member I3 which is arranged in contact with the curved face of the insulator. The arcuate member is secured to the insulator by a curved rod I4 which embraces the insulator in one of the annular depressions of said insulator, the opposite end portions of said 50 curved rod being extended through openings formed through Vportions of the arcuate member I3 and said opposite end portions of said rod being screw-threaded adjacent to their ends to receive nuts I5 which may be drawn up to cause 55 the curved rod and the arcuate member to tightly engage the insulator. The arcuate member I3 constitutes the lower terminal of the switch, being provided with an outwardly projected extension I6 which has associated therewith a suitable connector I'I through the instrumentality of which an electrical conductor (not shown) may be electrically connected to said extension.

The contact I2 preferably is formed from a single length of heavy wire and it includes an upwardly extended loop I8 at its inner end which is seated in a depression formed in the arcuate member I3 (Fig. l). 'I'he contact I2 is secured to the arcuate member by a bolt I8 whose shank extends through the loop I8 of the contact and into an opening formed in the arcuate member, said bolt shank extending also through an apertured disk 28 and a lock washer 2i. From the lower end of the loop I8 parallel portions 22 of the contact I2 extend forwardly and continuations of these parallel portions 22 are bent helically to provide the contact with opposed spring portions 23 which give to the contact the required resiliency.

The portions 22 of the contact I2 enter the centers of the helically Wound spring portions and leading from the lower, outer portions of said spring portions is a pair of parallel contact portions 24 which terminate in convergent portions 25. From the forward ends of the convergeht portions 25 parallel and relatively closely positioned contact portions 26 are extended forwardly and at the forward end of the contact these portions 25 are bent rearwardly upon themselves as indicated at 2l to provide gripping portions which are adapted to engage portions of fuse links as will presently appear herein. Extended from the rearwardly bent portions 2l are outwardly flared portions 28 which serve to guide fuse links into the gripping portions. In order to prevent undue spreading of the contact portions 26 sleeves 29 are provided which embrace said portions, and in like manner to prevent excessive outward movement of the rearwardly bent portions 2l a cap 38 is applied to the outer end portion of the contact in embracing relation with respect thereto.

The means for attaching the lower contact II to the insulator B comprises a member 3| which is provided with an arcuate face 32 (Fig. 4) that contacts with the curved outer face of the lower portion of the insulator B, said member being secured .to the insulator by a bolt 33 which extends through an opening formed through said member and through an aperture 34 formed through the wall of the hollow insulator B. Within the interior of the hollow insulator the bolt 33 has associated therewith a substantially V- shaped washer 35 which is interposed, as shown in Fig. 4, between the inner face of the insulator and a nut 36 mounted on the screwthreaded inner end of the bolt.

The lower contact II is constructed and arranged just as is the lower contact I2 which has already been described in detail herein; that is to say said lower contact I I includes an upstanding loop 31 at its inner end, opposed helically wound spring portions 38, spaced apart portions 38' which extend forwardly from the lower portions of the spring portions, convergent portions 38 and adjacently positioned, forwardly extended portions 40, and rearwardly bent portions 4I at the outer end of the contact which provide gripping portions and have ared guides 42 associated therewith. Likewise the contact II has sleeves 43 associated with the portions 48 thereof and a cap 44 applied to the outer end of the contact, the sleeves and cap being intended to prevent undue spreading of parts of the contact. The contact II is secured to the insulator by the bolt 83 heretofore referred to, the shank of said bolt passing through the upstanding loop 31 of the contact, as shown in Fig. 4, and a disk 45, which with a lock washer 48 is arranged beneath the y head of the bolt. being in engagement with said upstanding loop 3l.

The member 3| that supports the lower contact II includes an extension 4`I (Fig. 4) which supports a transfer contact 48. This transfer contact is made preferably of a single length of heavy wire possessed of resiliency and it includes an upstanding loop 48 from the lower end of which forwardly extended portions 58 are projected. At the forward ends of the portions 58 of the transfer contact 48 the length of wire from which the transfer contact is formed is bent upwardly as shown at 5I in Fig. 3. 'Ihe length of wire is then bent downwardly in parallelism with the portions 5I as shown at 52, and the remaining portions of the length of wire are bent upwardly in spaced relation with respect to the portions 52 as indicated at 53, the upper end portions of said portions 53 being flared outwardly to provide inclined guides 54. The transfer contact is provided with a sleeve 55 which prevents undue spreading of the portions 58 thereof, and said transfer contact is secured to the member 3| by a bolt 56 in the same general manner that the lower contacts I I and I2 are secured to the members 3| and I3.

The member 3| includes a bifurcated extension 51 as shown in Fig. 4 to which is pivotally attached a blade 58 of a knife switch. Also the member I3 includes an extension that supports an element 59 which includes opposed yieldable fingers between which an outer portion of the blade 58 may be moved to make electrical contact between the member I3 and the member 3|. For convenience of operation the switch blade 58 is provided with an enlarged outer end portion having an opening formed therein which may receive a suitable insulated tool for moving the switch blade into and out of electrical contact with the element 58.

In its fully fused condition the improved switch includes a pair of fuse links 68 and 8| of like construction and arrangement. Each of these fuse links comprises a pair of flexible cables 82 which are spaced apart at their inner ends to provide a gap, and a fusible element 63 which is electrically and mechanically connected to the inner end portions of said cables is disposed in said gap. The fusible element 53 and the adjacent inner portions of the flexible cables 62 of each fuse link are enclosed within a tube 84 which preferably is formed of horn fiber or other material that is characterized by the ability to give off a gas in the presence of the heat of an electric arc which tends to extinguish said electric arc. The tube 64 of each fuse link is interposed between and is supported by collars 54 that are secured to the cables G2. At the outer ends of the cables 62 of each fuse link loops 68 are formed and fixed to the flexible conductors in close proximity to the loops are stop buttons 61.

When the improved switch is fully fused the lower flexible cable of the fuse link 58 is drawn into one of the gripping portions at the outer end portion of the lower contact II, while the lower flexible cable of the fuse link 6I is drawn into one of the gripping portions at the outer end portion of the lower contact I2. These gripping portions, as has already been explained herein, are provided in the case of the lower contact II by the portions 4I) and 4|, and in the case of the lower contact I2 by the portions 26 and 21. Also when the lower flexible cables have been drawn into gripping portions ofthe lower contacts II and I2 as stated above, the lower stop buttons 61 contact with the under sides of said lower contacts. Furthermore during the fully fused position of the improved switch the upper flexible cables of the fuse links 60 and 6I are drawn into the gripping portions of the upper contact 3, the upper flexible cable of the fuse link 60 being drawn into the gripping portion at one side of the upper contact, and the upper flexible cable of the fuse link 6I being drawn into the gripping portion at the opposite side of the upper contact. The gripping portions of the upper contact are provided by the rearwardly bent portions 8 and adjacent portions of the forwardly extended portions of said upper contact. When the upper flexible cables of the fuse links 60 and 6I are drawn into the gripping portions of the upper contact 3 the buttons 61 associated with said upper flexible conductors contact with the upper side of the upper contact.

In assembling the fuse links 60 and 6I in place in the switch said fuse links are applied to the switch one at a time. Ordinarily the switch is located in an elevated position and when this is' so the operator passes the transverse finger of a switch stick through the loop at the upper end of the fuse link so that the link is suspended from said finger. He then raises the suspended fuse link and pulls it outwardly so as to draw the portion of the lower flexible cable immediately above the button 61 deep into the gripping portion of the lower contact with which the fuse link is being assembled. The operator then raises the fuse link to the proper elevation and then pulls the upper portion of said fuse link outwardly so as to draw the portion of the upper flexible cable deep in one of the gripping portions of the upper contact. When the operator raises theI fuse link with its lower end attached to a lower contact he winds the helical spring portions of the lower contact with the result that said lower contact is placed under considerable tension which tends to draw the outer end of the lower contact downwardly. When the first fuse link has been applied to the switchas described the second fuse link is assembled with the switch in like manner whereupon the switch is ready for use.

When the improved switch is fully fused and in use electrical energy passes from the terminal I through the upper contact to and through the fuse link 6I to the lower contact I2, and from said lower contact through the lower terminal I3 to conductor connected thereto. It is to be noted that when the switch is fully fused no current passes through the fuse link 60 due to the fact that the lower contact II is out of electrical connection with respect to the lower terminal I3. Now, if with the switch fully fused a fault occurs in the circuit, the fusible element 63 of the fuse link 6I will part and thereby release the tensioned lower contact I2 which will snap downwardly in response to action of the helical spring portions 23. This will quickly separate the severed ends of the fusible element 63 so as to quickly extinguish the electric arc produced by severance of the fusible element, such extinguishment of the electric arc being aided by the gas produced within the tube 64 when the horn fiber thereof is subjected to the heat of the electric arc.

When the outer portion of the lower contact I2 is snapped downwardly as described the forwardly extended portions 24 of said lower contact I2,move into the spaces between the upright portions 52 and 53 of the transfer contact 48. The course of the current then is from the upper terminal through the upper contact 3, to and through the fuse link 60 to the lower contact II. From the lower contact the current passes through member 3I with which the lower contact II is associated to the transfer contact 48 and from said transfer contact to and through the lower contact I2, which at this time contacts with the transfer contact 48, to the lower terminal and the conductor connected thereto.

The purpose of the knife switch of which the blade 58 forms a part is to avoid interrupting the circuit when a newi fuse link is being arranged in place in the switch after a previously operative fuse link has been blown. When a maintenance man discovers that the first fuse link has been blown and he desires to replace the blown fuse link with a new fuse link, he first moves the blade 58 into contact with the element 59. This provides a path for current from the member 3l to the lower terminal I3 and the maintenance man may then refuse the blown side of the switch and in so doing'draw the lower contact I2 out of electrical contact with the transfer contact 48 without interrupting the circuit. When'refusing of the blown side of the switch has been completed the blade 58 may be drawn out of contact with the element 59 whereupon the current will pass through the fuse link 6I and the switch will be in condition for its repeating action.

In Fig. 6 a form of the switch is illustrated which is adapted for direct attachment to a transformer. The switch of Fig. 6 is constructed substantially like the switch of Figs. 1, 2, and 3 with the exception that the switch of Fig. 6 is in an inverted position relative to the switch of Figs. 1, 2, and 3 and also the switch of Fig. 6 includes a fitting 65 at the lower end of the insulator B' which serves to connect the switch electrically and mechanically to a transformer. The switch of Fig. 6 includes a contact 3' which corresponds to the contact 3 of the switch A except that it is located at the bottom of the switch instead of at the top thereof. Also the switch of Fig. 6 includes contacts II and I2' which are electrically connected to the contact 3 by fuse links 60 and Likewise the switch of Fig. 6 includes a transfer contact 48' into contact with which the contact I2 moves when the fuse link 6I' blows. The switch of Fig. 6 as illustrated does not include a knife switch such as the one of which the blade 58 forms a part but obviously such a knife switch could be applied to the switch of Fig. 6

- if desired.

electrical connection with said terminal and supported so that its longitudinal length extends radially with respect to said insulating support, a pair of contacts supported in spaced relation with respect to said contact means, said pair of contacts being resilient and when drawn to tensioned positions portions of said pair of contacts tend to move in a direction away from said contact means, a second terminal arranged in electrical connection with one of the contacts oi said pair of contacts, a pair of fuse links electrically connected to said contact means and electrically connected to said pair of contacts in a manner to cause said pair of contacts to be drawn to tensioned positions, one of said fuse links being connected to one of said pair of contacts and the other of said fuse links being connected to the other of said pair of contacts and both of said fuse links being connected to said contact means, and means adapted on rupture of the fuse link associated with the contact which is electrically connected to the second terminal to place the other Contact of the pair of contacts in electrical connection with said second terminal, the last mentioned means comprising a transfer contact into contact with which the contact of said pair of contacts that is in electrical contact with said second terminal moves, said transfer contact being out of direct mechanical contact with said second terminal at all times and a portion of the contact which moves into contact with said transfer contact serving as the sole means for making electrical connection between said transfer contact and said second terminal.

2. A repeater fuse switch comprising an 'insulating support, a terminal, contact means supported by said insulating support in electrical connection with said terminal, a pair of contacts supported in spaced relation with respect to said Contact means, said pair of contacts being resilient and when drawn to tensioned positions portions o said pair oi contacts tend to move in a direction away from said contact means, a second terminal arranged in electrical connection with one of the contacts of said pair of contacts, a pair oi fuse links electrically connected to said contact means and electrically connected to said pair of contacts in a manner to cause said pair of contacts to be drawn to tensioned positions, one of said fuse links being connected to one of said pair of contacts and the other of said fuse links being connected to the other of said pair of contacts, and means adapted on rupture of the fuse link associated with the contact which is electrically connected to the second terminal to place the other contact of the pair of contacts in electrical connection with said second terminal, said means comprising a transfer contact having spaced portions between and in electrical contact with which the contact electrically connected with the second terminal moves.

3. A repeater fuse switch comprising an insulating support, a terminal, contact means supported by said insulating support in electrical connection with said terminal, a pair of contacts supported in spaced relation with respect to said contact means, said pair of contacts being resilient and when drawn to tensioned positions portions of said pair of contacts tend to move in a direction away from said contact means, a second terminal arranged in electrical connection with one oi the contacts of said pair of contacts and normally out of electrical contact with the other of said pair of contacts, a pair of fuse links electrically connected to said contact means and electrically connected to said pair of contacts in a manner to cause said pair of contacts to be drawn to tensioned positions. one of said ruse links being connected to one oi said pair of contacts and the other of said fuse links being connected to the other of said pair of contacts, and means adapted on rupture of the fuse link associated with the contact which is electrically connected to the second terminal to place the other contact of the pair of contacts in electrical connection with said second terminal, said means comprising a transfer contact arranged in electrical connection with the contact which is normally out of electrical connection with said second terminal and provided with spaced portions between and in electrical contact with which the contact electrically connected with said second terminal moves.

4. A repeater fuse switch comprising an insulating support, a terminal, elongated contact means in electrical connection with said terminal and supported so that its longitudinal length extends radially with respect to said insulating support, a pair of contacts supported by said insulating support in divergent relation and disposed in spaced relation with respect to said contact means, said pair of contacts being resilient and when drawn to tensioned positions portions of said pair oi' contacts tend to move in a direction away from said contact means, a second terminal arranged in electrical connection with one of the contacts of said pair of contacts, a pair of fuse links electrically connected to said contact means and electrically connected to said pair of contacts in a manner to cause said pair of contacts to be drawn to tensioned positions, one of said fuse links being connected to one of said pair of contacts and the other of said fuse links being connected to the other of said pair of contacts and both of said fuse links being connected to said contact means, and means adapted on rupture oi the fuse link associated with the contact which is electrically connected to the second terminal to place the other contact of the pair of contacts in electrical connection with said second terminal, the last-mentioned means comprising a transfer contact into contact with which the contact of said pair of contacts that is in electrical contact with said second terminal moves, said transfer contact being out of mechanical contact with said second terminal at all times and a portion of the contact which moves into contact with said transfer contact serving as the sole means for making electrical connection between said transfer contact and said second terminal.

5. A repeater fuse switch comprising an insulating support, a terminal, elongated contact means in electrical connection with said terminal and supported so that its longitudinal length extends radially with respect to said insulating ,support, a pair of contacts supported by said insulating support in divergent relation and disposed in spaced relation with respect to said contact means, said pair of contacts being resilient and when drawn to tensioned positions portions of said pair of contacts tend to move in a direction away from said contact means, asecond terminal arranged in electrical connection with one of the contacts of said pair oi' contacts, a pair of fuse links electrically .connected to said contact means and electrically connected to said pair of contacts in a manner to cause said pair of contacts to be drawn to tensioned positions, one of said fuse links being connected to one of said pair ot contacts and the other of said fuse links being connected to the other of said pair of contacts and both of said fuse links being connected to said contact means, opposed gripping portions forming parts of said contact means for receiving and engaging portions of said fuse links, and means adapted on rupture of the fuse link associated with the contact which is electrically connected to the second terminal to place the other contact of the pair of contacts in electrical connection with said second terminal, the last-mentioned means comprising a transfer contact into contact with which the contact of said pair of contacts that is in electrical contact with said second terminal moves, said transfer contact being out of mechanical contact with said second terminal at all times and a portion of the contact which moves into contact with said transfer contact serving as the sole means for making electrical connection between said transfer contact and said second terminal.

6. A repeater fuse switch comprising an insulating support, a terminal, elongated contact means in electrical connection with said terminal arranged in electrical connection with one of the contacts of said pair of contacts, a pair of fuse links electrically connected to said contact means and electrically connected to said pair of contacts in a manner to cause said pair of contacts to be drawn to tensioned positions, one of said fuse links being connected to one of said pair of contacts and the other of said fuse links being ccn-D nected to the other of said pair of contacts an both of said fuse links being connected to sai contact means, gripping. portions forming parts of said pair of contacts for receiving and engagu ing portions of said fuse links, opposed gripping;- portions forming parts of said contact means for: receiving and engaging portions of said fuse iinks, and means adapted on rupture of the fuse links associated with the contact which is electrically conected to the second terminal to place the other contact of the pair of contacts in electrical connection with said second terminai, the lastmentioned means comprising a transfer Contact into contact with which the contact of said pair of contacts that is in electrical contact with saidv second terminal moves, said transfer contact bem ing out of mechanical Contact with said second terminal at all times and a portion of the contact which moves into contact with said transfer contact serving as the sole means for making electrical connection between said transfer contact and said second terminal.

CHARLES ADIN FOX. 

